Three-dimensional printing is a technology of fast forming. Data of three-dimensional model designed by designer is inputted into a three-dimensional printer and a final object with respect to the data is formed by drawing out layer-by-layer material that includes adhesive materials of metallic powder or plastic. Such implementation by the three-dimensional printer is called additive manufacturing, which directly manufactures a three-dimensional physical model totally corresponding to a mathematical model by adding materials and layer-by-layer forming according to the three-dimensional STL model data. Such an approach is characteristic of manufacturing an object of any shape and totally different from traditional forming method by material removal.
Three-dimensional printing technology has been developing and being emphasized these years. There are more and more manufacturers developing three-dimensional printing technologies to meet various requirements. Qualities of a physical object may be judged by some standards in which the accuracy of a model is the most important indicator. The accuracy for a model indicates the degree of shape matching between the physical object and its model.
However, current three-dimensional printer lacks approaches of real-time detection accuracy and can only rely on passive ways such as on-site manual checking or remotely capturing photos. These passive ways often have drawbacks. For example, malfunction or errors can neither be detected or alarmed because of lack of real-time active detection, raising alarm and taking corrective action. The malfunction or errors then causes failures in printing and the wasting of time and material. Also, without quantifying the resulting degrees of matching, the accuracy of model shape cannot be objectively judged, so it only depends on subjective manual judgment.